1. Field of the Invention
The present invention relates generally to the co-production of hydrogen peroxide and another useful product, and more particularly, to an improved two-step process of producing hydrogen peroxide wherein an oxalate ester or a carbonate ester is also produced.
2. Description of the Prior Art
The production of hydrogen peroxide has generally been accomplished heretofore using the "anthraquinone process". The anthraquinone process is a two step process wherein in the first step, a substituted or unsubstituted anthraquinone is reduced with molecular hydrogen in the presence of a catalyst to an anthrahydroquinone. The anthrahydroquinone is separated from the catalyst and then reacted with air in the second step to form hydrogen peroxide and the starting anthraquinone which is recycled to the first step.
A number of processes have also been developed which involve the production of an oxalate ester by the oxidative coupling of carbon monoxide with an alcohol in the presence of a quinone. For example, United States Pat. No. 4,005,130 issued Jan. 25, 1977 discloses the preparation of an oxalate ester by the oxidative coupling of carbon monoxide and an alcohol in the presence of a catalytic amount of a copper, nickel, cadmium, cobalt or zinc metal salt and at least a stoichiometric amount of an unsubstituted or halogen substituted quinone.
U.S. Pat. No. 4,379,939 to Radel et al. discloses the production of an oxalate ester by the oxidative carbonylation of alcohol with carbon monoxide in the presence of a substituted or unsubstituted quinone, the production of oxamide (a potential fertilizer) from the oxalate ester, and the regeneration of the starting quinone by oxidation of the produced hydroquinone.
By the present invention, an improved two-step process for producing hydrogen peroxide is provided wherein another useful product in addition to the hydrogen peroxide is produced, i.e., either a product substantially comprised of an oxalate ester or a product substantially comprised of a carbonate ester.